Fluorobissulfonylmethyl Iodides: An Efficient Scaffold for Halogen Bonding Catalysts with an sp3-Hybridized Carbon–Iodine Moiety

The halogen-bond donors FBSM-I and FBDT-I, which contain an sp3-hybridized carbon–iodine (Csp3–I) moiety, were designed and synthesized. The highly electron-withdrawing nature of the fluorobissulfonyl-methane scaffold leads to the generation of σ-holes on the surface of the iodine atoms in FBSM-I and FBDT-I. Mukaiyama aldol reactions and hydrogen-transfer reductions are efficiently catalyzed by FBSM-I and FBDT-I under neutral and mild reaction conditions. The driving force for these transformations should be the halogen bonding induced by FBSM-I and FBDT-I, which was confirmed by DFT calculations, single-crystal X-ray diffraction analyses, and NMR titrations.